Face seals are used in gas turbine engines to prevent the leakage of fluid along rotating shafts where the shaft extends through a stationary structure such as a wall or partition. Referring to FIG. 1, a typical face seal is comprised of a stationary stator 22, having a flat surface that rubs against a flat surface of a rotating rotor 20. The rubbing of these surfaces generates significant amounts of heat and as a result thermal gradients within the rotor 20 form. These gradient must be properly managed to prevent leakage. A problem that can arise with rotors having the shape of rotor 20 is that under adverse thermal gradients rotor 20 will deform or cone. When this occurs the flat surface of the rotor 20 swings away from the flat surface of the stator 22 resulting in leakage.
One approach to this problem has been is to provide external or internal cooling of the rotor in the form of oil jets, cooling fins, or cooling passages. However, these approaches add significant complexity to the design of the rotor and are expensive. Another approach has been to make the rotor from a ceramic. A disadvantage to ceramics is their brittleness.
Accordingly, there is a need for a face seal having a rotor configured to be resistant to deformation when subjected to adverse thermal gradients.